EDEN PRAIRIE, Minn. -- Minnesota Vikings defensive end Jared Allen had 13.5 sacks a year ago through 11 games en route to finishing with 22, a half-sack behind the single-season record set by the New York Giants' Michael Strahan in 2001.

Allen has not been able to duplicate that success in 2012.

He hasn't had a sack in the past three games. He does have a team-leading seven, but that is almost seven fewer than he had at this time a year ago.

Allen has been on the Vikings' injury report in recent weeks. On Thursday, he was listed with shoulder and back issues, although he did not miss any practice time.

"I think everyone in the NFL at this time of year, when you're at the end of November going into December, I'm not sure that anyone in the league is healthy," Vikings defensive coordinator Alan Williams said when asked if he thought Allen's injuries have been a factor in the decline of his sack numbers. "Every player is working through some bumps and bruises and every player is a little leg weary.

"It's just a matter of who can sustain it and who can function well mentally and physically while they're a little bit beat up. I think Jared does a good job of doing that. He's a professional, he shows up every Sunday ready to go. They just have to work through those aches and pains during the week. Every player is going through the same thing Jared is going through right now."

Allen and Williams both point to the fact that the Vikings haven't been putting themselves in the best position to get sacks. Sacks come from putting the opposing team in a situation where they have to throw the ball, either because they are trailing in the game or because they are facing third-and-long.

The Bears, for instance, gave up six sacks to the 49ers in a 32-7 loss in Week 11. Chicago was only 3-for-12 (25 percent) on third down in that game. But in their 28-10 victory over the Vikings last Sunday, the Bears gave up only one sack and were 11-for-19 (58 percent) on third down.

On Sunday, the Vikings will face the Green Bay Packers at Lambeau Field. Much like the Bears' offensive line against San Francisco, the Packers line had some big-time problems last Sunday night in a 38-10 loss to the host New York Giants. Green Bay quarterback Aaron Rodgers was sacked five times.

Allen figures that means the Packers will provide maximum protection for Rodgers throughout the game. The Bears also frequently went that route last Sunday at Soldier Field.

"We led the league in sacks last year," Allen said. "It wasn't like we expected (the Bears) just to move out of the way and give them to us. But you've got to look at the way these games play out. If you can get a lead, you force them out of a lot of stuff. When you're 18 points behind, they can keep as many people in the box and one guy out.

"You look at the Giants game. They had a lead, Green Bay was forced to spread out and they were playing from behind. If we can get a lead, and we can force them to play from behind and we can force them to have to take shots downfield by being successful on first and second down, then you create some match-up (issues).

"If not it's going to be a tough road. You're going to deal with chip (blocks), you're going to deal with double teams, you're going to deal with the ball coming out quick, short shallow passing game, run game. The whole playbook is open. It's all situation football and you have to force them into situations and take advantage of it."

Allen has had plenty of success in his career getting to the quarterback against Green Bay. He has sacked Packers' quarterbacks 13 times, with 12.5 coming with the Vikings and against Aaron Rodgers. Allen had 7.5 sacks of Rodgers in two games in 2009 alone.

"If you want to be considered the best, you want to be able to play well against the best and Aaron Rodgers is considered one of the best quarterbacks in the league," Williams said when asked about Allen's success against the Packers. "I imagine, and I'm not speaking for Jared, that he does want to play well, and for a variety of reasons."

Allen said there is a reason that he has had an opportunity to get to Rodgers at times.

"He's such a good quarterback that sometimes he will hold the ball a little longer to make a great play," Allen said. "Sometimes that can work against him. You get a quarterback that is that good and sometimes you'll get to him because he holds it a little extra.

"Sometimes that burns you. ... Their offense is predicated on taking shots down the field and when you take shots down the field every once in a while you're going to give up a few sacks. I've just been blessed to be on the fortunate side of it sometimes."

No concerns

Blair Walsh had a 30-yard field-goal attempt blocked in the second quarter last Sunday by Julius Peppers, making it only the second field-goal the rookie kicker has failed to make this season. He is now 24 of 26 on field-goal attempts.

"(Walsh) did not get underneath it enough, he drove it a little bit far," Vikings special teams coordinator Mike Priefer said. "It was a great protection and they knocked it down. We told him, 'Peppers, that's the guy.' He did it to us last year; he's done it his whole career. I think he's got 13 blocks. They had really, virtually, no penetration. I thought we blocked it up pretty good. He just jumped straight up, timed it up perfect. On a low kick, you're going to knock it down."

Priefer said the block did not impact Walsh.

"He's a mentality tough kid, he really is," Priefer said. "That's one of the things I liked about him from day one, when I first met him. He'll be fine. ... He's not rattled at all.

"The great thing about Blair is that, first of all, I've been around young kickers and punters and young players that make excuses, 'I didn't do this because the grass.' Whatever, he made no excuses. He went over to the bench, 'Great protection fellas. It's my fault. We'll get it corrected.' And this next one, I think it was the (point-after touchdown), that thing was straight up in the air. He corrected it right away."

Quick hits

Wide receiver Donald Driver (thumb), linebacker Clay Matthews (hamstring), running back Johnny White (concussion), defensive end C.J. Wilson (knee) and tight end Andrew Quarless (knee) did not take part in Thursday's practice for the Packers. Defensive tackle Ryan Pickett (quadriceps), linebacker Terrell Manning (shoulder), tackle Marshall Newhouse (wrist) and safety Sean Richardson (back) were limited. Wide receiver Greg Jennings (groin/abdomen) was a full participant for a second day in a row and will play Sunday after missing the past seven games and eight of their last 10.